The principle of this circuit is simple, and it is easy to make. You can try it yourself. The self-made schematic diagram of the home physiotherapy instrument is as follows: power adapter from the power transformer, rectifier circuit, shell composition. 9V Power Adapter is a small power adapter, DC cable connector diameter (d) is 2.1mm, diameter (D) is 5.5mm, thickness (B) is 10mm. 5V Power Adapter is high-speed operation and durable, not easy to bad. These power adapter features: product size: 74 * 30 * 42mm, small size, streamlined, completely sealed, easy to carry.cost-effective, high reliability, ultrasonic pressure shell. built-in over voltage, overcurrent and short circuit protection. Products with strong anti-interference, to ensure the use of long life products, through the EMC test, ripple ≤ 50MV.Widely used in Monitor,router and other products.Output conventional voltage 5V 12V 24V 36V 48V, the other can be produced according to customer requirements. 9V AC DC Switching Power Adapter 9 Volt Dc Power Adapter,9 Volt Power Adapter,9 Volt Ac Adapter,9V Ac Power Adapter Shenzhen Juyuanhai Electronic Co., Ltd. , https://www.powersupplycn.com